API: vpp: add blend state for composition.

Add a new VABlendState structure that defines the blending operations for
composition. So far, only luma keying, alpha blending and premultiplied
alpha are supported.

Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>

Conflicts:
	va/va.h
	va/va_vpp.h
Added new attribute and data structure to support slice decoding base mode.

Conflicts:
	va/va.h
Add vaSurfaceAttribUsageHint to give the driver a hint of intended usage to optimize allocation (e.g. tiling).
Added support for VP8 encoding.

Conflicts:
	va/Android.mk
Removed fields in VP8 structures that duplicate VAEncMiscParameter structures. Added reference frames to support non auto reference frame implementation. Changed VAQMatrixBufferVP8 to use quantization index deltas.
va_enc_vp8: update the vp8 interface again

previous update missed some changes

Signed-off-by: Austin Yuan <shengquan.yuan@intel.com>
Add frame_type to VP8 encoder

From penne.y.lee at intel.com

Signed-off-by: Austin Yuan <shengquan.yuan@intel.com>